1. Technical Field
This disclosure is related to low-haze transparent conductive electrodes (Herein after “TCE”), and method for making the same.
2. Description of the Related Art
Transparent conductive electrodes are optically clear and electrically conductive films, comprising substrates and transparent conductive materials deposited on top of the substrates. The substrates can either be glass or plastic. The transparent conductive materials currently used in the art, are indium tin-oxide (ITO), aluminum doped zinc oxide (AZO), fluorine doped tin oxide (FTO), carbon nanotubes, graphenes, or metal nanowires.
Many commercial applications of transparent conductive electrodes, such as display applications, typically require both excellent optical properties, for example, high optical transmittance and low haze, and superior electrical properties, i.e. high conductivities or low sheet resistance. Most of the research effort in the field has been working towards how to balance the optical properties and electrical properties, as most of development has been found to improve one property at the sacrifice of the other.
In addition to electrical and optical properties of transparent conductive electrodes, physical or mechanical properties of the film, such as film hardness, are also important. It is well known that film hardness of a transparent conductive film is directly related to the production yield of the electronic devices. For example, when using metal nanowire based transparent conductive electrode to make touch screen device in a manufacturing scale, one of the significant factors contributing to the yield loss is the scratching or denting of the film in the manufacturing processes. However, most of the metal nanowire based transparent conductive electrodes in the prior art, for example, the transparent conductive electrode taught in U.S. Pat. No. 8,018,568, have metal nanowires embedded in a polymer matrix, such as polyurethane or acrylate polymers. The polymer matrix generally does not offer enough scratch, scuff or abrasion resistance.
In view of the foregoing, a harder metal nanowire based TCE film is needed. Here we present a low haze metal nanowire based conductive film that not only has excellent electrical properties but an optimized portfolio of optical and mechanical properties as well.